Use of passive acoustic recordings

to examine interactions of Northern

Spotted Owls (Strix occidentalis)

and Barred Owls (Strix varia)

Matt Hane

Weyerhaeuser NR

Springfield, Oregon

Raptor Research Foundation Conference

Sacramento, California

November 6, 2015

Background

• Reliability of traditional survey method

• How does Barred Owl presence affect

Spotted Owl calling behavior?

• Started in early 2014

• Still collecting data

Deployment at Five Spotted Owl

SitesWeyerhaeuser’s Coos Bay Tree Farm

Data Collection

• Wildlife Acoustics SM2+

• Two hours at sunrise and sunset

– Start 1.5 hours before sunrise

– Start 0.5 hour before sunset

– Sunrise to sunset every 8th day

• Lots of data

Preliminary System Testing

• Sensitivity of the microphones

• Reliable data

Range of

detection

Field test early

September 2014

Broadcast calls ~ 100

m

Barred owl pair ~ 200

m

Long Ridge

Lower Cat

Creek

Reliable Data

• Equipment failure

– dead batteries

– bad connections /

cables

– memory cards

– Song Meter

components

• Weather related

– Wind and rain

Results So Far

2014 2015

• Spotted owl nesting at

four sites

• No spotted owl nesting

• Preliminary work with

Song Scope Recognizers

Next Steps

• Continue building suitable recognizers

• Establish a cut off date

• Analyze

• Publish?

Thank You